Magnetic refrigeration technology at ambient temperature has been known for more than twenty years and the advantages that it provides in terms of ecology and sustainable development are widely acknowledged. Its limits in terms of useful calorific output and efficiency are also well known. Consequently, all the research undertaken in this field is directed at improving the performance of such a generator, by adjusting the various parameters, such as the magnetization power, the performance of the magnetocaloric element, the heat exchange surface between the heat transfer fluid and the magnetocaloric elements, and the performance of the heat exchangers, etc.
The French patent application no. 07/07612 by the applicant describes a magnetocaloric generator in which the thermal energy generated by magnetocaloric elements is exchanged with a heat transfer fluid that is displaced through the magnetocaloric elements by circulation means. These circulation means are in the form of pistons that are driven with reciprocating movement by a control cam having a specific cam profile.
This generator however presents a disadvantage that is inherent to driving these pistons. In fact, this drive is subjected to the wear of the components in contact, that is, the cam profile and the pistons, which can result in a premature degradation of the generator efficiency. Moreover, it poses problems of sealing between the piston sleeves and the drive mechanism.